1. Field of the Invention
The present invention relates, in general, to precision agriculture methods, and, more particularly, to software, systems and methods for real-time or near real-time nutrient management based upon plant tissue analysis.
2. Relevant Background
Plants require many nutrients to grow, blossom and fruit. Most preferably, the essential nutrients needed for plant nutrition are present in adequate amounts in the soil. More commonly, one or more of the essential nutrients must be added to the soil by application of fertilizers containing nutrients in which a particular soil is lacking. Under a number of growing conditions, essential nutrients may be present in the soil in sufficient quantities, but may not be readily accessible to the plants for uptake and translocation, in which case combinations of fertilizers and plant growth enhancing compounds are applied before, during and/or after planting.
The essential nutrients include macronutrients (e.g., nitrogen xe2x80x9cNxe2x80x9d, phosphorus xe2x80x9cPxe2x80x9d and potassium xe2x80x9cKxe2x80x9d) which are needed by plants in relatively large quantities. The essential nutrients also include secondary nutrients (calcium xe2x80x9cCaxe2x80x9d, magnesium xe2x80x9cMgxe2x80x9d and sulfur xe2x80x9cSxe2x80x9d) which are required in lesser quantities. Micronutrients are essential nutrients which are needed in very small amounts and include iron xe2x80x9cFexe2x80x9d, manganese xe2x80x9cMnxe2x80x9d, copper xe2x80x9cCuxe2x80x9d, zinc xe2x80x9cZnxe2x80x9d, molybdenum xe2x80x9cMoxe2x80x9d, chlorine xe2x80x9cClxe2x80x9d and boron xe2x80x9cBxe2x80x9d. Although important, over supply of micronutrients can lead to toxicity and significant production loss consequently the indiscriminate use of micronutrient supplements can have harmful results.
Nutrient management is an increasingly difficult and yet increasingly important task. According to a long-standing principle known as Liebig""s Law of the minimum, the yield of a plant is limited by the lack of a single nutrient even though there may be sufficient quantities of all the other essential nutrients. Waiting until plants show visible signs of a nutrient imbalance to establish which nutrient is limiting production, a condition often referred to as nutrient deficiency, is often too late to take effective remedial action. Plant yield has already been negatively impacted by a deficiency condition and even when the insufficiency can be remedied, production loss has occurred. All too often plants deficient in one or more nutrients cannot be saved. The challenge then is to proactively establish and supplement the nutrient or nutrients limiting production prior to the appearance of visual symptoms. Hence, the need for nutrient management systems and methodologies that enable practical treatment of nutrient shortfalls before they become deficiencies.
Historically, users managed nutrients using historical performance data and soil analysis. Before and sometimes after planting, nutrients are applied (e.g., nitrogen, zinc, etc.) to achieve soil nutrient levels matching previous seasons that had produced suitable results. However, plant requirements change from year to year, as a result of a number of environmental factors, and the ideal nutrient levels one year may produce sub-optimal results in another year. Further, nutrient management will be made more complex by increasingly strict regulations on the quantity and type of amendment that can be added directly to soil. Soil-applied nutrients tend to migrate into surrounding land and water supplies and may impact the ecosystem of these surrounding areas. As a result, regulations and self-imposed restrictions will limit the amount and timing of soil-applied nutrients.
Foliar nutrient supplements can be applied after planting to correct nutrient shortfalls. Foliar supplements are taken up into the plant much more efficiently than soil supplements, and therefore can reduce the amount of nutrients that must be added to the soil. Foliar supplements, however, are much more difficult to manage than soil supplements. Foliar supplements often benefit from sequential application of particular supplements at specific concentrations at specified time intervals. Some supplements may be applied at one time while others benefit from staggered application. Interactions between supplements and/or the crop protection products they are applied with may prevent application in certain combinations or at certain times during a growing season. Ideally, each case is managed individually to account for individual plant needs and production goals. However, selecting suitable nutrient supplements and timing schedules to correct particular nutrient shortfalls is problematic, time consuming, and generally beyond the capacity of the applicator responsible for managing the application.
In the past, foliar products were applied as a routine application where the particular products, and application timing were based upon a best guess or estimate of what was thought to be plant requirements at that time. Application rate of individual nutrients was kept low to guard against any danger of toxicity. This ad hoc approach does not take in to account variation in seasonal environmental factors. There is no attempt to target particular nutrients that may be short as a result of events of that season and therefore this method tends to produce inconsistent results from season-to-season. This approach fails to take into account the principles of Leibig""s Law in that there is no attempt to establish which nutrient or combination of nutrients is limiting production in the current plant under the environmental factors of that season. Applications of broad-spectrum nutrients are made hoping they contain some of the correct nutrient to address the problem and often fail to provide sufficient quantities of the required nutrient.
Historically, users would manage the levels of a handful of key nutrients within the soil. As technology progresses, the number of nutrients that can be managed becomes unwieldy, making it difficult to implement state-of-the-art information and knowledge into a nutrient program. Trace nutrients, in particular, are difficult to manage and may easily result in serious impact to plant production. Moreover, environmental conditions such as temperature and rainfall may temporarily affect nutrient uptake such that even with near ideal soil levels part of the plants potential is lost to malnutrition. Hence, a need exists for a system and method that readily enables users to develop a comprehensive, prioritized and orchestrated nutrition program that adapts to real-time plant needs.
Recent technological advances have resulted in farm management approaches generally referred to as xe2x80x9cprecision farmingxe2x80x9d. These approaches generally involve analysis of specific plant and soil needs. In practice, users can apply fertilizers, herbicides, and pesticides at variable rates within their fields in response to specific plant and soil needs, rather than a uniform rate without regard to plant variability. Precision farming techniques promise to increase farm profits and decrease environmental impact of farming.
In large part, precision farming involves remote sensing techniques to map within-field plant and soil conditions. While remote sensing has advantages of being able to analyze large areas of land quickly, the amount of information about specific plant and soil needs that can be derived from remote sensing is limited. Several techniques are available to detect nitrogen deficiency, for example, but comprehensive analysis of a variety of nutrients is not possible. Instead, remote sensing provides a means to distinguish healthy from unhealthy plants, leaving the user to institute remedial strategies for unhealthy plants manually.
Often, remedial action for a particular plant need must occur within days of identifying the need. The difficulty in assessing remedial procedures to identify suitable nutrient amendments delays the user""s response to arising issues such as excess rain, drought, or unusual temperature conditions and the like. Preferably, users need a system for identifying nutrient requirements and corrective measures before a deficiency becomes apparent and affects current plant production.
One method of obtaining detailed information about plant and soil needs is through laboratory analysis such as tissue analysis. Tissue analysis provides information about what nutrients the plant is actually obtaining from the soil and the effect of current weather on nutrient levels. In theory, in-season tissue analysis helps the user evaluate the effectiveness of an already applied nutrient program, and allows for corrective action to maximize a plant""s potential. This allows a nutrient program to be adapted to current plant and soil needs rather than being based on historical needs that may or may not be relevant to the current season.
Currently, the use of tissue analysis is sporadic at best, as producers generally know that testing is available but are unaware of a practical application. Those producers that do use tissue analysis generally use it late season and use it to evaluate their soil-applied fertilizer program. As well, there is very little use in field crops as most tests are done on higher value perennial crops. One problem with late-season analysis is that at this point there is little any one can do to correct nutritional shortfalls of the plant that impact both plant health and the current year""s production. The test simply provides a xe2x80x9csnapshotxe2x80x9d of the late season nutritional status of the plant under the environmental conditions of the last season (temperature, rainfall, crop load, hours of sunshine or any other naturally occurring events that impact how plants obtain nutrients). It is difficult to determine exactly what should be done the next year as it relates to soil-applied fertilizer rates. Any of the environmental factors can and will change and over application of some of the micronutrients can be toxic to the plant.
Another problem of this approach is that a single late-season analysis does not measure the requirements of the plant over time throughout the season. For example Boron is very important for the reproductive stage of the plant. The greatest need for this nutrient occurs at bloom and fruit set and even the number of blossoms on a plant can impact boron levels at that time-late season analysis can not measure boron levels at bloom nor does it provide any opportunity for correction. This is further complicated because environmental conditions that impact uptake may have changed dramatically from earlier in the season. Further, it is difficult to determine which nutrients are most important and need to be treated first in order to help improve the uptake of other nutrients. Hence, there remains a need for a plant nutrition system and method that alleviates this discomfort and provides sound, precise recommendations that growers can follow as a xe2x80x9cprescriptionxe2x80x9d for correct nutrition that are not only effective but are safe to the plants as well.
Users often prefer to manage nutrient levels to achieve particular results in their plants. Unfortunately, nutrient suppliers may supply recommended nutrient levels that have shown to provide suitable results, however, these recommended levels may not produce the user""s target and preferences. Hence, a need exists for a plant nutrition management system and method that enables user input to select target nutrient levels, and proscribes nutrient supplements to achieve those target levels.
Briefly stated, the present invention involves a system and method for translating plant tissue analysis results into nutritional supplement recommendations. A tissue analysis is performed on plant samples from a treatable area of plants. The tissue analysis results indicate current nutrient levels in the plant. The tissue analysis results are applied as inputs to rule-based logic that selects entries from an expert database. The expert database includes nutritional amendment information including selected specific products, application rates, and application intervals intended to restore the plant nutrient levels to desired values.